Capacitor discharge type contactless ignition system for internal combustion engines

ABSTRACT

A capacitor discharge type contactless ignition system for an internal combustion engine is provided in which the stored charge on a capacitor adapted to charge and discharge in one direction only, is discharged through the primary winding of an ignition coil, thus inducing a high voltage in the secondary winding of the ignition coil and providing an ignition spark to a spark plug connected to the secondary winding. The ignition system is so designed that any undesired storage action of the capacitors can be prevented to thereby ensure an excellent ignition advance characteristic and at the same time the developed voltage on the capacitors can be easily made uniform to thereby prevent any misoperation of the engine and ensure a reliable operation thereof.

United States Patent Nagasawa Sept. 9, 1975 [54] CAPACITOR DISCHARGE TYPE 3,598,098 8/1971 Sohneret a1. 123/148 MC CONTACT-LESS IGNITION SYSTEM FOR 3,648,675 3/1972 Gemander t 123/]49 R 3,722 488 3/1973 Swift v l23/149R INTERNAL COMBUSTION ENGINES 3.739.759 6/1973 Sleder 123/148 MC [75] Inventor: Masao Nagasawa, Kariya, Japan 3,791,363 2/l974 Schmaldienst 123/148 E N td., K [73] Asslgnee gs Co L anya Primary ExamznerManuel A. Antonakas p Assistant Examiner-Joseph Cangelosi [22] Filed: June 27, 1973 Attorney. Agent, or Firm-Cushman, Darby & 21 Appl. N0.: 374,097 Cushma [57] ABSTRACT [30] Forelgn Appllcatlon Prlorlty Data A t d h t u capacl or 15C arge ype contac ess ignition system June 29. 1972 Japan 4165674 for an internal Combustion engine is provided in which July 31, 1972 Japan... 47-90650 the stored charge on a capacitor adapted to charge Feb. 27 1973 Japan... 48-25508 and discharge in one direction only, lS discharged Mar. 13. 1973 Japan... 48-31381 through the primary winding of an lgmtlon 0011, thus Mar. 15, 1973 Japan 48-31852 mducmg a high voltage in the secondary winding of Mar. 20 1973 Japan 4834285 h d k Mar 27 1973 Japan 4847390 t e lgnltion col an provl mg an IgnlKlOfl spar to a spark plug connected to the secondary winding. The Us. Cl- I u 1 V I v I I 7 123/148 315/209 ignl ton syster? IShSO designed that anly undeslred stor 1 Int Cl p 00 age action 0 t e capacitors can e prevented to 58} i E 149 thereby ensure an excellent ignition advance charac o are teristic and at the same time the developed voltage on References Cited the capacitors can be easily made uniform to thereby prevent any mrsoperatlon of the engine and ensure a UNITED STATES PATENTS reliable operation thereof. 3,495,579 2/1970 Davalillo 123/149 R 3,554,179 6/1969 Burson I23/l49 A 20 Clams 60 Drawmg F'gures PATENTEDSEP 9M5 3,903,862

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PATENTED 91975 3. 903 8B2 SHEET FIG. 3

PAIENTED 94975 SHEET FIG. 7

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PATENTEB SEP 9 1975 SHEEI FIG. 9

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PATENTED 35? 91975 SHEET FIG.

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PATENTED 91975 3,903,862

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1. In a capacitor discharge type contactless ignition system for an internal combustion engine, used with a magneto generator, comprising: charging circuit means including capacitor charging coil means coupled to a magneto generator for generating an alternating current signal during rotation of said magneto generator, rectifying means for rectifying said alternating current signal of said capacitor charging coil means to produce halfwaves and a capacitor, said coil means rectifying means and capacitor being connected in series to permit current flow from said capacitor charging coil means through said rectifying means and said capacitor, discharging circuit means connected to said capacitor including semiconductor switching means having a control electrode and a primary winding of an ignition coil having said primary winding and a secondary winding, said capacitor switching means and primary winding being connected in series to cause the stored charge on said capacitor to discharge through said primary winding upon conduction of said switching means; a spark plug connected to said secondary winding; and ignition control means connected to said control electrode of said semiconductor switching means for sequentially generating ignition timing signals in synchronism with the rotation of an engine, the time between adjacent timing signals defining a cycle and including a plurality of half-waves, the improvement comprising; bypassing conduction means connected to said charging circuit means for preventing charging of said capacitor; and bypassing controlling means for causing said alternating current to by-pass said capacitor through said bypassing conduction means, when said engine is rotating in a normal direction, for all but a selected number less than all of half-waves of said alternating current signal, which will otherwise charge said capacitor, and which are produced by said capacitor charging coil means after said ignition timing signal during each cycle, said cycle having a duration from a certain ignition timing signal to the next ignition timing signal and starting from the point where said capacitor begins charging.
 2. An ignition system as set forth in claim 1, wherein said ignition control means is a transformer connected to said capacitor charging coil means.
 3. An ignition system as set forth in claim 1 wherein said ignition control means includes a timing signal generator having signal coil means coupled to said magneto generator for producing a sequence of ignition signals during rotation of said magneto generator; and inductor means, mounted in said magneto generator for inducing said ignition timing signal in said signal coil means.
 4. An ignition system as set forth in claim 3, wherein said bypasss controlling means includes second inductor means mounted in said magneto generator for inducing in said signal coil means a control signal.
 5. An ignition system as set forth in claim 1 wherein said bypassing conduction means includes means for connecting said semiconductor switching means to said bypass controlling means so that for each cycle all but one of said half-waves are passed through said switching means.
 6. An ignition system as set forth in claim 5, wherein said switching means is connected across both terminals of said capacitor charging coil means.
 7. An ignition system as set forth in claim 1 wherein said bypassing conduction means is connected in parallel with said capacitor.
 8. An ignition system as set forth in claim 1 wherein said capacitor charging coil means comprises two coils wound on different cores mounted in said magneto generator.
 9. An ignition system as set forth in claim 1, wherein said capacitor charging coil means generates at least three cycles of said alternating current for each revolution of said magneto generator, and said capacitor is charged with more than two half-waves of said alternating current.
 10. An ignition system as set forth in claim 1 wherein said capacitor charging coil means comprises two coils connected in parallel and out of phase by less than 180 degrees with each other.
 11. An ignition system as set forth in claim 1, further comprising: a second charging circuit means including a second capacitor charging coil means for generating alternating current; a second rectifying means for rectifying said alternating current of said second capacitor charging coil means and second capacitor, said second coil means, second rectifying means and second capacitor being connected in series to permit current flow from said capacitor charging coil means through said second rectifying means and said second capacitor; a second discharging circuit means connected to said second capacitor, including second semiconductor switching means having a control electrode and a primary winding of a second ignition coil having said primary winding and a secondary winding said second switching means second primary winding and second capacitor being connected in series to cause the stored charge on said second capacitor to discharge through said second primary winding upon conduction of said second switching means; a second spark plug connected to said secondary winding; a second ignition control means connected to said control electrode of said second semiconductor switching means of said second discharging circuit means for generating ignition timing signals in synchronism with the rotation of said engine, the time between adjacent signals defining a cycle and including a plurality of halfwaves; a second bypassing conduction means connected to said second charging circuit means for preventing charging of said second capacitor; and a second bypass controlling means for causing said alternating current of said second charging circuit means to bypass said second capacitor when said engine is rotating in a proper direction for all but one of said half-waves of said alternating current signal which will otherwise charge said second capacitor, and which are produced by said second capacitor charging coil means of said second charging circuit after said ignition timing during each cycle, said one cycle having a duration from a certain ignition timing signal to next ignition timing signal and starting from the point where said second capacitor begins charging.
 12. An ignition system as set forth in claim 11 wherein said second ignition control means is a transformer whose primary winding is connected in parallel with said second capacitor charging coil means and whose secondary winding is connected to said control electrode of said second semiconductor switching means.
 13. An ignition system as set forth in claim 11, wherein said second ignition control means includes a timing signal generator having signal coil means coupled to said magneto generator for producing a sequence of ignition signals during rotation of said magneto generator; and inductor means, mounted in said magneto generator for inducing said ignition timing signal in said second signal coil means.
 14. An ignition system as set forth in claim 13, wherein said second bypass controlling means includes second inductor means mounted in said magneto generator for inducing in said second signal coil means a control signal.
 15. An ignition system as set forth in claim 11, wherein said second bypass controlling means is said capacitor charging coil means.
 16. An ignition system as set forth in claim 11 wherein said second capacitor charging coil means comprises two coils wound on different cores mounted in said magneto generator.
 17. An ignition system as set forth in claim 11 wherein said bypass controlling means comprises; signal generating means mounted in said magneto generator; and a transformer connected in said second charging circuit means, and said second bypass controlling means comprises; further signal generating means mounted in said magneto generator; and a transformer connected in said second charging circuit means.
 18. An ignition system as set forth in claim 1 further comprising: second charging circuit means including a second capacitor charging coil means coupled to said magneto generator for generating an alternating current signal during rotation of said magneto generator, a second rectifying means for rectifying said alternating current signal of said second capacitor charging coil means to produce half-waves and a second capacitor said second coil means, second rectifying means and second capacitor being connected in series to permit current flow from said second capacitor charging coil means through said second capacitor; a second discharging circuit means connected said second capacitor to said semiconductor switching means having said control electrode and a primary winding of a second ignition coil having said primary winding and a secondary winding, said second capacitor, switching means and second primary winding being connected in series to cause the stored charge on said second capacitor to discharge through said primary winding of said second ignition coil upon conduction of said switching means; a second spark plug connected to said secondary winding; second bypassing conduction means connected to said second charging circuit means for preventing charging of said second capacitor; and a second bypass controlling means for causing said alternating current signal of said second capacitor charging coil means to bypass said second capacitor through said second bypassing conduction means both when said engine is rotating in a proper direction for all but one of said half-waves of said alternating current signal, which will otherwise charge said second capacitor, and which are produced by said second capacitor charging coil means after said ignition timing signal during each cycle, said cycle having a duration from a certain ignition timing, to next ignition timing signal and starting from the point where said second capacitor begins charging.
 19. An ignition system as set forth in claim 1, further comprising; a second charging circuit means including means connecting a second capacitor to said capacitor charging coil'' means, a second rectifying means for rectifying said alternating current signal and said second capacitor, said charging coil means, second rectifyIng means, and second capacitor being connected in series to permit current flow from said capacitor charging coil means through said second capacitor; a second discharging circuit means connected to said second capacitor, including a second semiconductor switching means having a control electrode and a primary winding of a second ignition coil having said primary winding and a secondary winding, said second capacitor, second switching means and second primary winding being connected in series to cause the stored charge on said second capacitor to discharge through said primary winding of said second ignition coil upon conduction of said second switching means; second spark plug connected to said secondary winding; second bypassing conduction means connected to said second charging circuit means for preventing charging of said second capacitor; and second bypass controlling means for causing said alternating current of said capacitor charging coil means to bypass said second capacitor through said second bypassing conduction means when said engine is rotating in a proper direction for all but one of said half-waves of said alternating current signal, which will otherwise charge said second capacitor, produced at said capacitor charging coil means after said ignition timing signal during each cycle, said cycle having a duration from a certain ignition timing signal to next ignition timing signal and starting from the point where said second capacitor begins charging.
 20. An ignition system as set forth in claim 1, further comprising; a second discharging circuit means connected to said capacitor including a second semiconductor switching means having a control electrode and a primary winding of second ignition coil having said primary winding and a secondary winding, said capacitor, second switching means and second primary winding being connected in series to cause the stored charge on said capacitor to discharge through said primary winding of said second ignition coil upon conduction of said second semiconductor switching means; a second spark plug connected to said secondary winding of said second ignition coil; a second bypassing conduction means connected to said second charging circuit means for preventing charging of said capacitor; and, a second bypass controlling means for causing said alternating current signal of said capacitor charging coil means to bypass said capacitor through said second bypassing conduction means when said engine is rotating in a proper direction for all but a selected number less than all of said half-waves of said alternating current signal, which will otherwise charge said capacitor, and which are produced by said second capacitor charging coil means after said ignition timing signal during each cycle, said cycle having a duration from a certain ignition timing signal to next ignition timing and starting from the point where said capacitor begins charging. 